Ceramic fibres are also often called either RCF (Refractory Ceramic Fibre) or ASW (Alumina Silicate Wool) fibres and are especially pure high temperature glass fibers (HTGF). Ceramic fibres are characterized by high flexibility, extreme less weight, less thermal conductivity and heat storage. Ceramic fibres have excellent thermal shock resistance and are suitable for permanent high temperature use at critical conditions. Due to the purity ceramic fibres have a high chemical resistance with regard to a lot of substances (except Fluoride and Phosphorous compounds, Alkalis) and are available in many different product forms and classification temperatures typically in between 1250° C and 1600°C.